The cash-strapped clothing chain has hired a consultant to warn its factory workers about labor unions as an effort to organize the company’s workforce escalates, The Post has learned.

Starting last week, restive workers at the retailer’s LA-area factories — hit by layoffs and furloughs since the departure of controversial founder Dov Charney — have been corralled into a series of rotating, closed-door meetings, sources said.

Groups of about 20 workers at a time are warned that a labor union, among other things, would eat into their paychecks with forcible membership dues, according to several attendees.

The meetings have been orchestrated by Hilda Delgado, founder of HMD Consulting Group, which advertises on its site experience in “labor communications, and crisis and issues management.”

So far, the presentations have won a mixed reception from the company’s rank and file, insiders said. Many remain fiercely loyal to Charney, whose long-running “Legalize LA” campaign for migrant workers was as integral to his legacy as the company’s racy marketing.

“They took us to meetings inside the company to intimidate us,” American Apparel factory worker Ana Amador told The Post in a phone interview Wednesday.

“They’re saying those of us that have been organizing are on the outside, that we’ve been provoking this,” said Amador. “The truth is, we’re on the inside.”

The unionization effort is being backed by Hermandad Mexicana, a migrant worker advocacy group. Founded in 1951, the group doesn’t use contracts and member dues have always been a voluntary affair, according to senior adviser Nativo Lopez.

The group has signed up about 1,200 of American Apparel’s more than 3,000 factory workers, Lopez said. He’s aiming for two-thirds of the workforce — a chunk that management couldn’t ignore, he said.

The labor unrest has been fueled by American Apparel’s moves to conserve cash with furloughs and layoffs as it scrambles to reverse steep sales declines.

The company said it will meet a $13.7 million debt payment this month with the help of Standard General, a New York hedge fund that backed Charney’s ouster in December after taking control of the board.

Upwards of 200 employees gathered for a spontaneous rally Wednesday outside the company’s LA headquarters, many of them in tears as they protested a surprise round of 180 layoffs earlier in the day, attendees said.

Several workers told The Post that their supervisors had warned them that signing union authorization cards could lead to termination — a company action that would amount to a violation of federal labor law.

“These allegations are categorically false,” an American Apparel spokeswoman said in a written response. “We support our employees’ rights to express their views, and are committed to engaging in an active dialogue with them.”

A source close to the company’s management added that Delgado was “a multilingual consultant” hired to “facilitate open conversations about changes at American Apparel in an effort to better understand employee concerns and what we can do to address them.”

Nevertheless, many workers gathered at Delgado’s meetings have been told to be silent, according to Lopez.

“They’re told to be quiet and to listen to her presentation,” Lopez told The Post. “It’s really heavy-handed. There’s not even a Q&A.”

American Apparel workers say they’ve been subjected to surveillance, with guards and supervisors monitoring group conversations at workstations, in break rooms and in parking lots — a charge the company denied in a March 26 memo to employees.

“We have never — and will never — threaten employees for attending meetings,” the memo stated.

This month, Amador filed a complaint with the National Labor Relations Board, claiming she was “accosted and interrogated” by American Apparel security about an off-site meeting she attended Feb. 16 to discuss recent cuts in hours.